Carburetor for internal-combustion engines



DeC. 24, 1929. H, BECK CARBURETOR FOR INTERNAL GOMBUSTION ENGINES Filed July '7. 1926 lllllllllll .lll III I llslll Patented Een 24, 1.929

faillit? 'TS ENT QFFECE HOWARD BECK, 0F POCATELLO, DAHO, ASSIGNOR OF I'TNE-TENTHS T0 MYRON HURBQ''GI'I, OF BLESS, IDAHO CARBURETOR FOR NTERNAL-COMBUSTION ENGINES Application filed July 7,1925. Serial No. 120,999.

This invention relates to carburetors for internal combustion engines and more particular y to a means for producing within the float chamber of the carburetor a partial vacuum regulating the flow of fluid from the float chamber and facilitating the flow of fluid thereto.

An important object of the invention is to provide in a construe ion of this character means whereby a regulatable vacuum may be producen in the float chamber.

A still further object of the invention is to provide a construction such that the throttle valve of the carburetor controls the degree of vacuum within the float chamber.

These and other objects I attain by the construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a preferredA embodiment of my invention and wherein rllhe figure is a sectional view through a carburetor embodying` vacuum control means constructed in accordance with my invention.

Referring now more particularly to the drawings, the numeral 10 generally designates a simple carburetor and 11 the fuel bowl thereof. The carburetor includes a throat 12 within which is arranged an atomizer 13 which is supplied from the fuel supply chamber through a port 14 connecting the fuel supply chamber and atoinizer. rl`he fuel chamber has arranged therein the usual float 15 and needle valve 16 operated thereby to control the intake of fuel to the bowl from a fuel supply line 17. These bowls are usually threaded at their upper ends to permit flow of the fuel to the atomizer.

In accordance with my invention, the bowl 11 is sealed against the admission of air, eX- cept in a manner hereinafter set forth. rfhe throat of the carburetor has arranged therein at its discharge end 18 or that end which is connected to the manifold 19 of the engine a throttle valve 2O of the butterfly type. Adjacent the throttle valve, one wall of the carburetor is provided with a protrusion 21, the inner face of which is arcuately curved at 22 with the axis of the throttle valve shaft 23 as a center. rlhe adjacent portion of the perirn' diately adjacent this arcuately curved face and the valve when closed aligns with one edge of this curved face. ln alignment with the protrusion 21, the exterior wall of the carburetor is provided with a lug 24 having a threaded axial bore 25 which is intercepted adjacent its end by a radial bore 2G, the outer end of which communicates with the atmosphere. Threaded within the bore 25 is a screw 27, the position of which in the bore regulates the effective opening of the bore 26. rEhe head 2S of the screw has coacting therewith a spring 29 whereby it is held against rotation.

Connecting the curved face 22 with the inner end of the bore 25 is a port 3() which tapers toward the bore 25. The valve 20 provided upon the perimeter thereof has an arcuately curved flange 31 seating against the face 22 and sealing the inner end of the port when the valve is in the closed position. The free end of this flange may be connected with the body of the valve by a brace 32, if so desired.

Connecting the smaller end of the port 3() with the interior of the bowl 11 is a duct 33. It will be seen that the flanged extension of the valve 2O acts as a valve, controllingl the size of the port 30, with the result that as the valve 20 is progressively opened, the effective size of the port 30 is progressively increased. A paruial vacuum, always present in the outlet end of the carburetor throat while the engine is in operation, will, therefore, be transferred to the duct 33 and accordingly to the bowl of the carburetor in proportion to the degree of opening of the throttle valve. This vacuum is, however, partially broken by air admitted through the port 26, with the result that a state of balance is provided, wherein the vacuum applied to the nozzle 13 to draw fuel from the bowl is slightly greater than the vacuum produced wit-hin the bowl. Therefore. while the vacuum produced within the bowl will act to facilitate intake of fluid to the bowl, it will not interfere with the passage of fuel therefrom and, as a mat-ter of fact, will increase the uniformity of the flow from the bowl to the throat. The degree of vaciuun maintained within the bowl may be readily determined by an adjustment ofthe screw 27.

It will be obvious that the construction hereinbefore set forth is capable of a certain range of change and modification without materially departing from the spirit of the invention and I accordingly do not limit myself to such specific structure except as hereinafter claimed.

I claim In combination with a carburetor having a l nozzle and a throttle valve, a closed fuel bowl having a port communicating with the nozzle, a duct leading from the bowl, a conneetion between said duct and the atmosphere, a second connection between said duct and the throat of the carburetor adjacent the throttle valve, the connections between the throat of the carburetor and said duct 4 opening through a portion of the wall of the throat arcuately curved with the axis or" rotation of the throttle valve as a center, the throttle valve having an arcuate flange litting said wall and completely closing the mouth of the connection when the throttle valve is closed, said mouth being enlarged an d of greater width than the thickness of the throttle valve, the connection between said duct and the atmosphere comprising a threaded bore communicating with said duct, a port opening into the wall of the threaded bore and a screw adjustable in said threaded bore for determining the effective size of said port.

In testimony whereof I hereunto a'h'ix my signature.

HOWARD BECK. 

